diff options
| -rw-r--r-- | passes/opt/muxpack.cc | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/passes/opt/muxpack.cc b/passes/opt/muxpack.cc index f01d5474d..b6f3313bf 100644 --- a/passes/opt/muxpack.cc +++ b/passes/opt/muxpack.cc @@ -302,8 +302,12 @@ struct MuxpackPass : public Pass { log(" muxpack [selection]\n"); log("\n"); log("This pass converts cascaded chains of $pmux cells (e.g. those create from case\n"); - log("constructs) and $mux cells (e.g. those created by if-else constructs) into \n"); - log("into $pmux cells.\n"); + log("constructs) and $mux cells (e.g. those created by if-else constructs) into\n"); + log("$pmux cells.\n"); + log("\n"); + log("This optimisation is conservative --- it will only pack $mux or $pmux cells with\n"); + log("other such cells if it can be certain that the select lines are mutually\n"); + log("exclusive.\n"); log("\n"); } void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE |